The Miami Marlins have announced significant roster changes ahead of upcoming games, designating infielders Matt Mervis and Ronny Simón for assignment while adding outfielder Heriberto Hernández and infielder Jack Winkler to their 40-man roster. These moves, reported by Craig Mish of the Miami Herald and Kevin Barral of Fish on First, create critical roster space as the team prepares for the next phase of the season. The Marlins’ decision to designate Matt Mervis designated for assignment by Marlins highlights a shift in priorities given recent player performances.
Detailed Look at Matt Mervis’s Performance and Future with the Team
Matt Mervis, 27, acquired from the Chicago Cubs in December in exchange for Vidal Bruján, began his Marlins tenure with promising power hitting. By April 23, he had already launched seven home runs but struggled with a high strikeout rate of 36.2%. Since then, Mervis’s slump worsened, with no home runs and an increased strikeout rate climbing to 38.5%. Over his major league career, which combines time with both the Cubs and Marlins, Mervis’s slash line stands at a disappointing .165/.238/.322 with a strikeout rate of 34.5% over 261 plate appearances.
Despite stellar minor league numbers in 2022 and 2023, where he hit .297/.388/.576, Mervis has found it difficult to adjust at the major league level. His strikeout problem intensified in 2024, extending to his Triple-A performance, where he posted a 30% strikeout rate. While his bat shows power potential, Mervis primarily plays first base—a position that demands consistent hitting to maintain roster value. With Eric Wagaman currently slotted as the regular first baseman despite a modest .227/.277/.382 stat line, the Marlins appear to be moving on from Mervis.
Mervis will now enter a seven-day period under the designated for assignment (DFA) process, during which the Marlins may trade him or expose him to waivers. If claimed, he could be assigned to a minor league team, where there remains a chance for a turnaround given his still intact minor league options.
Ronny Simón’s Brief Major League Appearance and Next Steps
Ronny Simón, 25, recently added to the Marlins’ 40-man roster from a minor league deal, has also been designated for assignment. Simón’s 56 plate appearances with the team yielded a .234/.327/.277 stat line. He was thrust into an intense spotlight after a difficult game against the San Diego Padres, where defensive errors contributed to the Marlins squandering a 6-0 lead and losing 8-6. During that game, Simón was seen wiping tears from his face, but he subsequently received warm support from teammates and even rival players such as Manny Machado, Luis Arráez, and Fernando Tatís Jr.
Simón’s minor league statistics this season suggested potential: he hit .354/.441/.521 in 15 Triple-A games, though some of that success was buoyed by an unsustainably high batting average on balls in play (.410 BABIP). His patient approach at the plate was evident in a 15% walk rate and a relatively low 16.7% strikeout rate. Previously regarded by FanGraphs as one of the top 20 prospects in the Tampa Bay Rays’ system, Simón did not break through with the Rays and became a free agent before signing with Miami. Known for his versatility as a switch-hitter capable of covering multiple infield positions and stealing 20 to 35 bases annually, he still carries minor league options, which may influence his next destination following the DFA process.
Jack Winkler Earns First Major League Promotion
Jack Winkler, 26, has been called up to the majors for the first time in his career. The Marlins acquired Winkler from the Oakland Athletics during the minor league phase of last November’s Rule 5 draft. This season, he has hit .275/.331/.423 at Triple-A, aided by a .351 BABIP, and stolen 15 bases. Winkler’s defensive versatility is a valuable asset, with experience at all four infield positions and both corner outfield spots. Although never regarded as a top-tier prospect, his steady performance has earned him this opportunity to contribute at the highest level.
Looking Ahead: Implications of Marlins’ Roster Moves
The choice to designate Matt Mervis designated for assignment by Marlins and Ronny Simón underscores Miami’s urgency to improve roster efficiency amid inconsistent performances. Promoting Heriberto Hernández and Jack Winkler signals the organization’s investment in players with potential to stabilize the lineup and add flexibility in both the outfield and infield. How the DFA process unfolds over the coming week will reveal whether Mervis or Simón find new opportunities elsewhere or remain within the Marlins’ system.
As the season progresses, these moves could reshape the Marlins’ roster dynamic, offering a mix of experienced players and rising prospects. Fans and analysts will be watching closely to see if Hernández and Winkler can seize their chances, while Mervis and Simón face the challenge of adapting to new circumstances within or outside Miami’s organization.